1. Field of the Invention
The subject application generally relates to a mobile device, and more specifically, relates to a mobile device including an IPMC (Ionic Polymer Metal Composite) for adjusting an effective resonant length of an antenna element.
2. Description of the Related Art
With the progress of mobile communication technology, mobile devices, for example, portable computers, mobile phones, multimedia players, and other hybrid functional portable electronic devices, have become more common. To satisfy the demand of users, mobile devices usually can perform wireless communication functions. Some devices cover a large wireless communication area, for example, mobile phones using 2G, 3G, and LTE (Long Term Evolution) systems and using frequency bands of 700 MHz, 850 MHz, 900 MHz, 1800 MHz, 1900 MHz, 2100 MHz, 2300 MHz, and 2500 MHz. Some devices cover a small wireless communication area, for example, mobile phones using Wi-Fi, Bluetooth, and WiMAX (Worldwide Interoperability for Microwave Access) systems and using frequency bands of 2.4 GHz, 3.5 GHz, 5.2 GHz, and 5.8 GHz.
In a mobile device, an antenna element is an essential component for wireless communication. To cover multiple bands, in the conventional design, some electronic components (e.g., diodes) are often incorporated into the antenna element and used as switches. These switches are configured to adjust the resonant length of the antenna element. However, these electronic components generally cannot form perfect shorted-circuits or perfect open-circuits while they are switching, and therefore they may increase power consumption and degrade the radiation performance of the antenna element.